1. Technical Field
The disclosure relates to an endoscope device and a method for operating the endoscope device. The disclosure also relates to a computer-readable recording medium.
2. Related Art
Conventional techniques have been known in which an endoscope device with a flexible elongated insertion unit to be inserted into a living body (a lumen such as the large intestine) of a human and the like which observes the inside of the living body by using an image sensor provided at a distal end of the insertion unit is provided with a pressure sensor and a variable stiffness mechanism on the insertion unit (for example, refer to JP 3752328 B2).
The endoscope device disclosed in JP 3752328 B2 is provided with a plurality of pressure sensors and a plurality of variable stiffness mechanisms for each section (hereinafter, referred to as segment) arranged in an axial direction of the insertion unit. The endoscope device operates the variable stiffness mechanism of the segment to decrease stiffness of the segment (soften the segment) when the pressure sensor of a certain segment is pressed by a body cavity wall at the time of insertion of the insertion unit into the living body.
However, the endoscope device disclosed in JP 3752328 B2 may cause the following situation.
FIGS. 18A to 18C are schematic views for illustrating a conventional endoscope device 100. Specifically, FIGS. 18A to 18C sequentially illustrate a state of an insertion unit 200 when an operator of the insertion unit 200 applies insertion force to the insertion unit 200 of the endoscope device 100 inserted into the large intestine in a distal end direction.
As illustrated in FIG. 18A, suppose that the insertion unit 200 is inserted into the large intestine and a certain segment 211 (a segment 210 widely bent in FIG. 18A) of the insertion unit 200 abuts on a body cavity wall WA of a bent portion in the large intestine.
In this case, a pressure sensor of the segment 211 is pressed by the body cavity wall WA, so that the endoscope device 100 operates a variable stiffness mechanism of the segment 211 to decrease stiffness of the segment 211. As a result, a bending amount of the segment 211 further increases according to the amount of the insertion force applied by the operator to the insertion unit 200 as illustrated in FIG. 18B.
Herein, the pressure sensor of the segment 210 other than the segment 211 is not pressed by the body cavity wall WA. That is to say, the stiffness of other segments 210 is not changed. Therefore, when the operator applies the insertion force to the insertion unit 200, the bending amount of the segment 211 increases but the bending amounts of other segments 210 do not increase and the segment 211 in an acute-angled shape pushes the body cavity wall WA as illustrated in FIG. 18C. That is to say, even when the insertion force is applied to the insertion unit 200, the shape of the segment 210 other than the segment 211 does not change, and the insertion force is merely converted to force to extend the large intestine (to push the body cavity wall WA). Hence, propulsion in the distal end direction is scarcely generated and it is not possible to pass through the bent portion of the large intestine. In addition, a subject may suffer pain by the push on the body cavity wall WA.